1. Field of the Invention
The present invention relates to a magnetic module for a power inductor, a power inductor, and a manufacturing method thereof.
2. Description of the Related Art
An inductor is a key passive element constituting an electronic circuit, together with a resistor and a capacitor. An inductor is used in a component or the like, to cancel noise or form an LC resonance circuit. Inductors may be classified as winding type inductors, laminated type inductors, thin film type inductors, and the like.
The winding type inductor may be formed by winding a coil around a ferrite core, or the like.
The winding type inductor may have stray capacitance between coils, and accordingly, in the case of increasing the number of turns of a coil to obtain higher inductance, degradation in high frequency characteristics may be caused.
A laminated type inductor may be formed by laminating a plurality of ferrite sheets.
In the laminated type inductor, coil-like metal patterns are formed on respective ferrite sheets, and the coil-like metal patterns may be sequentially connected by a plurality of conductive vias provided in the ferrite sheets.
The laminated type inductor is appropriate for mass-production and has excellent high frequency characteristics compared with a winding type inductor.
However, in the laminated type inductor, metal patterns are formed of a material having a low saturation magnetization value, and when the laminated type inductor is manufactured to have a small size, the number of laminations of the metal patterns is limited, resulting in lowered DC superposition characteristics and a failure to obtain a sufficient current.
A thin film type inductor may use a material having a high saturation magnetization value and even in the case that a thin film type inductor is manufactured to have a small size, an internal circuit pattern thereof may be easily formed in comparison to a laminated type inductor. Thus, recently, research into the thin film type inductor has been actively undertaken.
When a thin film type inductor is manufactured to be large, a coil may have a large thickness, thereby eliminating degradation in product characteristics due to an increase in series resistance.
However, when a thin film type inductor is manufactured to have a small size, an increase in the line width or thickness of a coil is limited, such that series resistance increases to degrade product characteristics.
Related Art Document 1 does not disclose a configuration in which recesses are formed in both surfaces of a substrate to lower series resistance while maintaining a certain inductance value.